insvasive species

Officials at the U.S. Army Corps of Engineers Chicago District say they plan to pump up the electricity at their fish dispersal barrier along the Chicago Ship and Sanitary Canal. The increase is intended to repel smaller fish.

From the U.S. ACOE's statement:

While extensive research and monitoring indicate that small Asian carp currently are not currently within the vicinity of the fish barrier, and all field telemetry research indicates the barrier is highly effective, the Corps is taking this conservative approach to operating the electrical dispersal barrier out of an abundance of caution.

Corps officials say they'll turn up the power "later this fall."

In the statement, Corps officials say they have an aggressive monitoring program and have tracked nearly "1.9 million detections of tagged fish in the barrier area, with no indication of tagged fish having crossed any of the electric barriers in the upstream direction."

Environmental DNA (eDNA) evidence was found above the barrier leading some to wonder whether the fish are establishing themselves in waters close to the Great Lakes.

Officials at the Corps say while DNA testing has some advantages, but "eDNA does not provide conclusive proof of the physical presence of live fish."